かしこい・お金・の・決断Make smarter money decisions.
Precise calculators and calmly-written guides for UK mortgages, tax, pensions and savings — built with British rigour, German engineering and Japanese restraint.
Calculators
Four tools · Updated for 2026/27Mortgage
Calculator.
Calculate monthly payments, total interest, and affordability for UK mortgages.
Avg. monthly · £300k @ 5.5%
Total interest · 25-yr term
Tax
Calculator.
Estimate income tax, National Insurance, and take-home pay for UK taxpayers.
Savings
Calculator.
Plan your savings goals with compound interest calculations for UK accounts.
Stamp Duty
Calculator.
Calculate stamp duty land tax for UK property purchases.
By the numbers
What we ship todayUK calculators live — mortgages, tax, savings, stamp duty
Explainer articles in the resource library
Current UK tax year coverage — updated as HMRC releases figures
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UK House Prices Up 2.7% in the Year to May 2026 — the First Post-SDLT-Change Comparison
ONS UK House Price Index: annual growth of 2.7% to May 2026, with the 0.3% monthly rise measured against last year's SDLT-driven 1.5% spike. What the May reading means for stamp duty.
Read the full piece